title: Positional dependency and surgical success of relocation pharyngoplasty among patients with severe obstructive sleep apnea.
abstract: OBJECTIVE
  To examine the effect of positional dependency on surgical success among patients with severe obstructive sleep apnea (OSA) following modified uvulopalatopharyngoplasty, known as relocation pharyngoplasty.
  
  
  METHODS
  Case series with planned data collection.
  
  
  METHODS
  Tertiary referred center.
  
  
  METHODS
  Standard nocturnal polysomnography was used to compare the apnea-hypopnea index (AHI) in different sleep positions before and after relocation pharyngoplasty in 47 consecutive patients with severe OSA (AHI, 59.5 ± 18.2 events/hour; Epworth Sleepiness Scale [ESS] scores, 12.2 ± 4.4) who failed continuous positive airway pressure therapy. Positional (dependency) OSA was defined when the supine:non-supine AHI ratio was >2, otherwise it was defined as nonpositional OSA. Surgical success was defined as a ≥50% reduction in AHI and a postoperative AHI of ≤20 events/hour. Polysomnographic parameters, ESS, and surgical success following surgery were recorded.
  
  
  RESULTS
  Of the 47 patients, 27 (57%) had positional OSA and 20 (43%) nonpositional OSA. The nonpositional OSA patients had higher AHI and ESS scores than the positional OSA patients (P = .002 and .104, respectively). Relocation pharyngoplasty significantly improved AHI and ESS scores in both positional and nonpositional OSA groups 6 months postoperatively (P < .05). The overall surgical success rate was 49%; however, positional OSA patients had a significantly higher success rate than nonpositional OSA patients (67% vs 25%, P = .008).
  
  
  CONCLUSIONS
  The presence of positional dependency at baseline was a favorable outcome predictor of surgical success among severe OSA patients undergoing relocation pharyngoplasty.
authors.affiliation: Department of Otolaryngology, Sleep Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
authors.forename: Hsueh-Yu
authors.initials: HY
authors.lastname: Li
authors.forename: Wen-Nuan
authors.initials: WN
authors.lastname: Cheng
authors.forename: Li-Pang
authors.initials: LP
authors.lastname: Chuang
authors.forename: Tuan-Jen
authors.initials: TJ
authors.lastname: Fang
authors.forename: Li-Jen
authors.initials: LJ
authors.lastname: Hsin
authors.forename: Chung-Jan
authors.initials: CJ
authors.lastname: Kang
authors.forename: Li-Ang
authors.initials: LA
authors.lastname: Lee
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D010614:Pharynx / Q000503:physiopathology / Q000601:surgery*; D017286:Polysomnography; D011187:Posture / Q000502:physiology*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: obstructive sleep apnea; outcome; positional dependency; relocation pharyngoplasty; sleep position